The invention relates to a coil device with a coil winding for an electromagnetic actuating device or an electromagnetic sensor, for example an ABS sensor in a motor vehicle, having a wire provided with an insulating, which wire is led to at least one contacting element that is designed as a metal stamped part, and a stripped section, in particular an end section, of the winding wire is received at said contacting element between the contacting element and a metal cover and fused to the contacting element.
The invention further relates to an electromagnetic actuating device or an electromagnetic sensor with a coil winding and a production method for producing the coil device.
From DE 20 2006 011 904 U1 an electromagnetic actuating device is known, which has a fixed coil device for adjusting an elongated actuator when current is applied. The coil device comprises here a plastic carrier with a coil winding arranged thereon, wherein the ends of the winding wire are each run to a contacting element and are fused thereto. Usually a so-called plate welding method (a resistance welding method) is used for fusing, in which the winding wire end is received between the contacting element and a metal plate and then, by application of the metal plate with a current impulse, is fused to the contacting element. During the welding process, at the same time a fusing of the metal plate to the contacting element also takes place.
In the previously described resistance welding method which is known per se, the electrode, which is clamped in a welding head, presses the metal plate with a defined force onto the copper wire which is applied onto the contacting element and in so doing impresses a recess (wire inlet) into the plate, which recess receives the winding wire end. After reaching the set force, the winding wire is connected by a current pulse with a flat region of the contacting element by fusing and is, in so doing, stripped of insulation. So that, before the application of the metal plate with a current pulse, the wire inlet can be impressed into the metal plate by the application of force of the metal plate by means of the electrode, a corresponding geometry must be provided in the electrode. This geometry is comparatively liable to wear, which leads to a small service life quantity of the electrodes which come into use. The electrodes must be frequently refinished, wherein for this, in practice, the front face of the electrode must be reset and the geometry must be newly milled in.
In the known method also the quality assurance or respectively checking of the welding plates by means of image processing software after welding is problematic. The three-dimensional, impressed geometry contains differently reflective free-form surfaces. In addition, the plate geometry alters with increasing electrode wear.
In a further, alternative, resistance welding method known from practice, for the materially-connected connection of a coil winding wire with contacting elements, metal plates separate from the contacting element are not fused to the contacting element, but rather a bendable lug, provided laterally on the contacting element, which after bending encloses the winding wire end together with the actual contacting element. In this method, a chamfered electrode is used, i.e. an electrode which has an effective area not running perpendicular to the direction of application of force, in order to impress the bent lug such that an optimized clamping of the winding wire end is ensured, or respectively that a mount for the wire is impressed. In this method also a not insignificant wear of the chamfered front area (effective area) results of the welding electrode which is used, which leads to short lifetimes and a laborious reprocessing of the effective area.
Proceeding from the above-mentioned prior art, the invention is based on the problem of indicating an alternative coil device which is distinguished by being able to be produced simply. In addition, the electrodes coming into use for the production of the coil device are to be distinguished by less wear. As a whole, the production costs are to be reduced. Preferably, an image processing examination of the metal cover, in particular of a metal plate or a metal lug which is less liable to error is to be possible in a simplified manner after welding.
In addition, the object consists in indicating a correspondingly improved, more favourably priced production method ensuring a long service life quantity of the electrodes, for the production of a coil device.
Advantageous further developments of the invention are disclosed hereinbelow. All combinations of at least two of the features disclosed in the description and/or the figures fall within the scope of the invention. To avoid repetitions, features disclosed with regard to the device are also to be deemed as disclosed and claimable with regard to the method. Likewise, features disclosed with regard to the method are to be deemed as disclosed and claimable with regard to the device.